With roughly 8k users (and roughly 10k visitors per day), you're bound to get the occasional sloppy tag.
When a bad tag is found, the best solution is to edit it into a good tag as soon as possible before it ends up getting used more: This is one reason the editing privilege is so fundamentally important to the Stack Exchange model (even anonymous users are allowed to suggest edits). Fixing one or two uses of a bad tag is a fairly trivial exercise for anyone (and I mean anyone) who cares to suggest an edit, but fixing a tag that's been applied to a hundred questions typically requires the direct intervention of a moderator (who then has the wonderful task of trying to sort out what to do with a bad tag that's also apparently a useful tag and a popular tag)
Whenever possible, I try to use Wikipedia's "Standard Transliteration" "Basic Transcription" (and would recommend everyone else do the same, as argued here). And tag-wise, I encourage having tags for English terms (as well as other common languages e.g. Urdu) synonymed to the transliterated Arabic, since not everyone who uses the site would necessarily know the proper Arabic terminology. So, for example, I've just applied the following:
This way, even if a new question adds the tag hell or caliphate, it'll apply jahannam or khilafah instead.
Variant transliterations, ideally, would just be edited to match the "standard" one whenever they crop up. However, variants that are particularly common or that just keep cropping up can be added as new synonyms on a case-by-case basis.
